NSC NSC Electrical Safety 2

Question 1

At what current level (in milliamps) can electrical shock cause ventricular fibrillation in the human heart?

Accepted Answer

100 mA

Answer

Currents as low as 100 milliamps (0.1 ampere) passing through the chest region can cause ventricular fibrillation and death.

Question 2

What color is the ground wire in a standard US three-prong electrical cord?

Accepted Answer

Green or bare copper

Answer

In US wiring, the ground wire is green or bare copper, the neutral is white, and the hot wire is black.

Question 3

What is the primary purpose of a lockout/tagout (LOTO) procedure related to electrical safety?

Accepted Answer

To de-energize electrical equipment and prevent accidental re-energization during maintenance

Answer

LOTO procedures isolate energy sources and lock them out so equipment cannot be accidentally re-energized while workers perform maintenance.

Question 4

Which type of PPE is classified as 'dielectric' and protects workers from electrical shock?

Accepted Answer

Rubber insulating gloves rated for the voltage class

Answer

Rubber insulating gloves with an appropriate voltage class rating are classified as dielectric PPE and protect against electrical shock.

Question 5

According to NSC guidelines, what should workers do before using portable electric tools?

Accepted Answer

Inspect the tool and cord for visible damage, fraying, or missing ground prongs

Answer

Workers must visually inspect portable tools and their cords for damage, fraying, or missing grounding prongs before each use.

NSC Practice Test